Day 1: Discussion of information from site and process plant visit The first day onsite allows the audit procedure to be described and a general exchange of information with site. The afternoon consists of a walk round of the process areas with appropriate staff to review location, layout of process plant, hazardous material storage, occupied buildings etc. Day 2: Review of bowties with appropriate site participants This is a classroom day when the pre-populated bowties are reviewed in detail and modified to reflect the actual equipment and practices onsite. There are also discussions with staff on the strength of the barriers claimed. Day 3 and 4: Review of actions from bowties and review of process safety elements